Clock



FIG. 1 is a front-right-top perspective view of a clock, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right elevational view thereof, the left side view being a mirror image;

FIG. 5 is a top plane view thereof; and,

FIG. 6 is a bottom plane view thereof. 

The ornamental design for a clock, as shown and described. 